Rotatable coaxial coupling



Get. 29, 1968 A. T. CLARKSON ROTATABLE COAXIAL COUPLING Filed April 10, 1967 INVENTOR.

ANTHONY T. CLARKSON BY ermag & 1610a:

United States Patent 3,408,610 ROTATABLE COAXIAL COUPLING Anthony T. Clarkson, 5655 N. Maria Drive,

ucson, Ariz. 85704 Filed Apr. 10, 1967, Ser. No. 629,723 6 Claims. (Cl. 339-8) a free running hearing within the coupling parts themselves.

Background of the invention The present invention relates to electrical connectors and specifically to a rotatable coupling for coaxial cables.

excessive. Summary" of the invention In the coupling described herein the center contact is maintained in abutting, free turning relation Without the use of an actual spring, while the shield or ground connection is made by a wiper element having a plurality of resilient fingers of different, non-harmonic lengths.

Brief description of the drawing FIGURE 1 is a side elevation view of the coupling in a typical use;

FIGURE 2 is an enlarged sectional view taken on line 22 of FIGURE 1; and

FIGURE 3 is a perspective view of the multiple finger wiper element.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawing.

Description of the preferred embodiment The coupling comprises an elongated, generally cylin- 3,408,610 Patented Oct, 29, 1968 securely against angular shifting and eliminates the need for a second bearing, while also holding proper axial relation so that proper contact Within sleeve 12 is an insulated plug 32 held conductive post 36, the outer end of which has a connecting pin 38 disposed within a tion and degrade the signal.

Barrel 10 has a reduced size bore 44 extending axially of sleeve 12. To minimize friction and 64 may have an outwardly projecting dimple 68 adjacent the tip thereof to make the actual concontact wall 66 wear each finger tact. All of the fingers 64 are of dilferent lengths and, considering the fingers as reeds, are of nonharmonic resonant frequencies, so that vibration of one finger will not cause vibration of any other. This arrangement also spreads the contact axially over wall 66 and further reduces wear. The outer end of cylindrical portion 62 has a protruding locking lug 70 which seats in a correspondingly shaped notch 72 in plug 46 and holds the wiper element against rotation.

Coaxial connectors of various types are in common use and the coupling is readily adaptable to any type. As illustrated, the outer end of barrel has a flange 74 to hold a flanged connector 76 and the outer end of sleeve 12 has a similar flange 78 to hold a flanged connector 80.

In normal use the barrel 10 will be attached to a convenient support While the sleeve 12 is allowed to rotate as necessary. A typical arrangement, shown in FIGURE 1, uses a bracket 82 through which barrel 10 fits, the barrel being secured to the bracket by nuts 84 on threaded portion 20. The actual mounting will depend on the particular use.

It is most unlikely that the rotational speed of the coupling will be high enough to cause resonance, the usual causes being outside sources, such as associated electrical apparatus, or electromagnetic fields in the coaxial line. Any tendency of any one finger 64 to vibrate will be damped out in the unitary wiper element and no undesirable electrical noise will be introduced into the coaxial line. Since no spring is used in the coupling there is no problem of inductance from the effect of a coil in the electrical field. Further, there is no alternating or layered structure of conductive and insulative material which could cause undesirable capacitance in the coupling. The very simple structure makes the coupling economical to manufacture and easy to service, all parts subject to wear being easily replaceable.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

I claim:

1. A rotatable coaxial coupling comprising:

a barrel element having means for connection to a coaxial cable;

a sleeve axially rotatably mounted in said barrel and having means for connection to a coaxial cable:

,- sgosp o a wiper element electrically connecting said barrel to saidsleeve, said wiper element having a plurality of resilient fingers frictionally engaging said sleeve and said fingers being of different lengths.

2. The structure of claim 1, wherein said fingers are resonantly non-harmonic with respect to each other.

3. The structure of claim 1, wherein said barrel and said sleeve are conductive; a

a conductive post axially mounted in said sleeve and insulated therefrom;

a conductive center pin axially mounted in said barrel and insulated therefrom;

and pressure means biasing said center pin into abutting contact with said post. 1 v t 4. The structure of claim 3 and including an insulated plug in said sleeve in which said post is fixed;

21 second insulated plug in said barrel in which said center pin is axially slidable, said center pin having an enlarged portion between said second plug and the post contacting end thereof;

and said pressure means comprising a resilient ring compressed between said second plug and said enlarged portion.

5. The structure of claim 4, wherein said wiper element has a cylindrical portion fitting tightly in said barrel, said fingers being integral with and extending axially from said cylindrical portion;

said sleeve having an internal contact face, concentric with said post, on which said fingers are frictionally engaged.

6. The structure of claim 1, wherein said sleeve is mounted in one end of said barrel, said sleeve having an annular bearing channel coincident with said one end of the barrel;

a collar adjustably mounted on said barrel and having an inwardly thickened flange closely concentric with said sleeve adjacent said one end of the barrel;

the confronting portions of said flange and said one end being oppositely bevelled and forming, with said bearing channel, a raceway;

and a plurality of ball hearings in said raceway.

References Cited UNITED STATES PATENTS 5/1938 Kus 3/1964 Cook 

